<template>
  <div class="carousel">
    <ul class="carousel-body">
      <li
        class="carousel-item"
        v-for="(item, i) in sliders"
        :key="item.id"
        :class="{ fade: i == index }"
        @mouseenter="stop()"
        @mouseleave="start()"
      >
        <router-link v-if="item.hrefUrl" :to="item.hrefUrl">
          <img :src="item.imgUrl" alt />
        </router-link>
        <div v-else class="slider">
          <router-link v-for="goods in item" :key="goods.id" :to="`/product/${goods.id}`">
            <img :src="goods.picture" alt />
            <p class="name ellipsis">{{ goods.name }}</p>
            <p class="price">&yen;{{ goods.price }}</p>
          </router-link>
        </div>
      </li>
    </ul>
    <a
      href="javascript:;"
      class="carousel-btn prev"
      @click="toggle(-1)"
      @mouseenter="stop()"
      @mouseleave="start()"
    >
      <i class="iconfont icon-angle-left"></i>
    </a>
    <a
      href="javascript:;"
      class="carousel-btn next"
      @click="toggle(1)"
      @mouseenter="stop()"
      @mouseleave="start()"
    >
      <i class="iconfont icon-angle-right"></i>
    </a>
    <div class="carousel-indicator">
      <span
        @click="index = i"
        v-for="(item, i) in sliders"
        :key="i"
        :class="{ active: i === index }"
        @mouseenter="stop()"
        @mouseleave="start()"
      ></span>
    </div>
  </div>
</template>

<script>
import { onUnmounted, ref, watch } from "vue"

export default {
  name: 'Carousel',
  props: {
    sliders: {
      type: Array,
      default: () => []
    },
    autoPlay: {
      type: Boolean,
      default: false
    },
    duration: {
      type: Number,
      default: 3000
    }
  },
  setup(props, context) {
    const index = ref(0)

    // 自动播放轮播图
    let timer = null
    const autoPlayFn = () => {
      clearInterval(timer)
      timer = setInterval(() => {
        if (++index.value > props.sliders.length - 1)
          index.value = 0
      }, props.duration)
    }

    watch(props.sliders, (newVal) => {
      if (props.autoPlay && newVal.length) {
        autoPlayFn()
      }
    }, { immediate: true })

    // 鼠标控制轮播
    const start = () => {
      if (props.autoPlay && props.sliders.length)
        autoPlayFn()
    }
    const stop = () => {
      if (timer)
        clearInterval(timer)
    }

    // 指示器切换
    const toggle = step => {
      let newIndex = index.value += step
      if (newIndex > props.sliders.length - 1)
        index.value = 0
      if (newIndex < 0)
        index.value = props.sliders.length - 1
    }

    onUnmounted(() => {
      if (timer)
        clearInterval(timer)
    })

    return {
      index,
      start,
      stop,
      toggle
    }
  }
}
</script>

<style scoped lang="less">
.carousel {
  width: 100%;
  height: 100%;
  min-width: 300px;
  min-height: 150px;
  position: relative;
  .carousel {
    &-body {
      width: 100%;
      height: 100%;
    }
    &-item {
      width: 100%;
      height: 100%;
      position: absolute;
      left: 0;
      top: 0;
      opacity: 0;
      transition: opacity 0.5s linear;
      &.fade {
        opacity: 1;
        z-index: 1;
      }
      img {
        width: 100%;
        height: 100%;
      }
    }
    &-indicator {
      position: absolute;
      left: 0;
      bottom: 20px;
      z-index: 2;
      width: 100%;
      text-align: center;
      span {
        display: inline-block;
        width: 12px;
        height: 12px;
        background: rgba(0, 0, 0, 0.2);
        border-radius: 50%;
        cursor: pointer;
        ~ span {
          margin-left: 12px;
        }
        &.active {
          background: #fff;
        }
      }
    }
    &-btn {
      width: 44px;
      height: 44px;
      background: rgba(0, 0, 0, 0.2);
      color: #fff;
      border-radius: 50%;
      position: absolute;
      top: 228px;
      z-index: 2;
      text-align: center;
      line-height: 44px;
      opacity: 0;
      transition: all 0.5s;
      &.prev {
        left: 20px;
      }
      &.next {
        right: 20px;
      }
    }
  }
  &:hover {
    .carousel-btn {
      opacity: 1;
    }
  }

  // 轮播商品
  .slider {
    display: flex;
    justify-content: space-around;
    padding: 0 40px;
    > a {
      width: 240px;
      text-align: center;
      img {
        padding: 20px;
        width: 230px !important;
        height: 230px !important;
      }
      .name {
        font-size: 16px;
        color: #666;
        padding: 0 40px;
      }
      .price {
        font-size: 16px;
        color: @priceColor;
        margin-top: 15px;
      }
    }
  }
}
</style>